GM1 gangliosidosis is a rare disease for which there is a limited understanding of disease progression and meaningful outcome measures. In addition, parents report that clinic-based assessments are not always well-suited to capture all the disease features and other metrics that have an impact on the patient and family. To address the methodological challenges of this small, heterogeneous population, this study will collect patient-specific home-based video data and qualitative interviews with caregivers.

This is a natural history study, for up to 2 years, during which parents or guardians of a child with GM1 gangliosidosis collect video data of patients doing specific daily life activities at baseline and follow-up timepoints throughout the study (3, 6, 12, 18, and 24 months) and/or submit videos taken in the past through a secure smart phone mobile application. The video assessments focus on several hallmarks of GM1 gangliosidosis progression. Caregivers participate in qualitative interviews to provide context for the videos and discuss any changes they observe during the study. Activity videos will be evaluated by expert clinicians using both Clinical Global Impression of Severity (CGI-S) and Clinical Global Impression of Change (CGI-C) scales. The caregiver interviews and clinician-rated activities will inform the patient-specific disease trajectories for each hallmark. There is no treatment or intervention associated with this study.

Inclusion Criteria:

Be or have been the parent, legal guardian, or caretaker of a patient with GM1 gangliosidosis with:

1. Early infantile GM1 gangliosidosis
2. Late infantile GM1 gangliosidosis
3. Juvenile GM1 gangliosidosis who can walk with assistance or possesses past videos of when child could walk with assistance
4. Early or late infantile GM1 gangliosidosis who has passed away, but is in possession of videos documenting the onset and evolution of disease hallmarks of GM1 gangliosidosis

Exclusion Criteria:

GM1 gangliosidosis patient that the caregiver cares for is being treated with any experimental medication in a clinical trial setting.

Study population will consist of children or adolescents